diff --git a/tests/unit/daemon/zone.t.cpp b/tests/unit/daemon/zone.t.cpp
index ed57285..f492782 100644
--- a/tests/unit/daemon/zone.t.cpp
+++ b/tests/unit/daemon/zone.t.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2020, Regents of the University of California.
+ * Copyright (c) 2014-2022, Regents of the University of California.
  *
  * This file is part of NDNS (Named Data Networking Domain Name Service).
  * See AUTHORS.md for complete list of NDNS authors and contributors.
@@ -21,11 +21,7 @@
 
 #include "boost-test.hpp"
 
-#if BOOST_VERSION >= 105900
 #include <boost/test/tools/output_test_stream.hpp>
-#else
-#include <boost/test/output_test_stream.hpp>
-#endif
 
 namespace ndn {
 namespace ndns {